Initial commit: ContactSync Android app

- SyncAdapter with account type com.bitrix24.contacts.sync
- Two-phase sync: download to Room DB, then import to phone contacts
- FCM push for instant contact addition
- WorkManager: periodic sync (30min) + heartbeat (1h)
- QR code activation (JSON format)
- Event log UI with LiveData
- Auto-update mechanism via version.php
- Duplicate contacts cleanup
- CALLER_IS_SYNCADAPTER optimization for bulk inserts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+android.useAndroidX=true
+kotlin.code.style=official
+android.nonTransitiveRClass=true